Mechanism of the antiviral effect of hydroxytyrosol on influenza virus appears to involve morphological change of the virus

Antiviral Res. 2009 Jul;83(1):35-44. doi: 10.1016/j.antiviral.2009.03.002. Epub 2009 Mar 24.

Abstract

Hydroxytyrosol (HT), a small-molecule phenolic compound, inactivated influenza A viruses including H1N1, H3N2, H5N1, and H9N2 subtypes. HT also inactivated Newcastle disease virus but not bovine rotavirus, and fowl adenovirus, suggesting that the mechanism of the antiviral effect of HT might require the presence of a viral envelope. Pretreatment of MDCK cells with HT did not affect the propagation of H9N2 virus subsequently inoculated onto the cells, implying that HT targets the virus but not the host cell. H9N2 virus inactivated with HT retained unaltered hemagglutinating activity and bound to MDCK cells in a manner similar to untreated virus. Neuraminidase activity in the HT-treated virus also remained unchanged. However, in the cells inoculated with HT-inactivated H9N2 virus, neither viral mRNA nor viral protein was detected. Electron microscopic analysis revealed morphological abnormalities in the HT-treated H9N2 virus. Most structures found in the HT-treated virus were atypical of influenza virions, and localization of hemagglutinin was not necessarily confined on the virion surface. These observations suggest that the structure of H9N2 virus could be disrupted by HT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / drug effects
  • Animals
  • Antiviral Agents / pharmacology*
  • Cell Line
  • Cytoplasm / ultrastructure
  • Dogs
  • Influenza A Virus, H1N1 Subtype / drug effects
  • Influenza A Virus, H3N2 Subtype / drug effects
  • Influenza A Virus, H5N1 Subtype / drug effects
  • Influenza A Virus, H9N2 Subtype / drug effects
  • Influenza A virus / drug effects*
  • Influenza A virus / ultrastructure*
  • Newcastle disease virus / drug effects
  • Phenylethyl Alcohol / analogs & derivatives*
  • Phenylethyl Alcohol / pharmacology
  • RNA, Viral / biosynthesis
  • Rotavirus / drug effects
  • Viral Proteins / biosynthesis
  • Virion / ultrastructure
  • Virus Assembly / drug effects
  • Virus Attachment / drug effects
  • Virus Replication / drug effects

Substances

  • Antiviral Agents
  • RNA, Viral
  • Viral Proteins
  • 3,4-dihydroxyphenylethanol
  • Phenylethyl Alcohol